A. Field of the Invention
The present invention relates generally to an electric dry shaver and more specifically to a new cutter assembly for attachment to the cutter drive mechanism of the shaver. The cutter assembly is fabricated as a modular assembly and positioned in the shaver head on the cutter drive mechanism as an assembled modular unit. The cutter assembly is assembled by the interfitting of a number of cutter blade elements and blade spacers in a predetermined interrelationship in a cutter support member.
B. Description of the Prior Art
In the electric dry shaver field, there are various types of shaving heads. One type of shaver in extensive use utilizes shearing elements formed by the interaction of oscillating or movable cutter assemblies with a stationary comb structure.
For example, the following U.S. patents describe cutter assemblies of this type: U.S. Pat. No. 3,791,030 which issued to Jackson, et al. on Feb. 12, 1974; No. 3,590,482 which issued to F. L. Carr on July 6, 1971; No. 3,401,453 which issued to C. L. Bauer on Sept. 17, 1968; No. 3,349,263 which issued to Jepson, et al. on Oct. 24, 1967; No. 3,196,539 which issued to Jepson, et al. on July 27, 1965; No. 3,208,141 which issued to Jepson, et al. on Sept. 28, 1965; and No. 2,688,184 which issued to Jepson, et al. on Sept. 7, 1954.
The cutter assemblies in the above referenced U.S. Patents are typically assembled by the insertion or attachment of individual cutting blades into supporting structure affixed to the movable cutter shafts in the shaving head.
For example, in Bauer U.S. Pat. No. 3,401,453, the individual cutting blade elements are inserted into various slotted portions of a blade support frame secured to the cutter shafts. Individual spring arms or levers are provided and extend from the blade support to provide the spring biasing of the cutter blades when individually inserted.
Another cutter assembly of this general type described in Jepson, et al. U.S. Pat. No. 3,208,141 includes integrally formed and downwardly depending hook shaped portions on the individual cutter blades for engaging and locking around triangular shaped, spaced blade support members. The blade support members are rigidly fastened to the cutter shaft by the passage of the cutter shaft through a circular opening in the support. The support includes spaced, slotted members; one for each of the cutting blade members. The depending hooked portions of each of the cutter blades are interlocked around additional slotted portions of the blade supports. Elongated wire spring members are disposed between the support members and the bottom of each of the blades to resiliently support the cutter blades.
While these types of cutter assemblies described hereinbefore are generally suitable for their intended use and application, the manufacturing assembly steps and the replacement of the individual cutter blades and the cutter assemblies in the field by service personnel and customers is relatively complex and costly.
Further, the inconsistency in the positioning and the repositioning during replacement of the cutter blades, springs and cutter support members results in increased lapping time during manufacture, the requirement for thicker comb structures and the necessity for frequent cleaning. The cleaning is made difficult by the many slots and open portions of the cutter assemblies exposed to the hairs falling through the comb assembly as shaving takes place. The cleaning tools may also deform or displace the various spring structures and subassembly parts altering the characteristics of the component parts.